I've answered your question on polish newsgroup on which You posted the
same post - plase in next posting to multiple groups use Follow-Up To
option and please use corect language.
<from polish newsgroup>
And answering Your question - read through migration quide, one of first
steps is to migrate excahgne 5.5 to excahnge 2k is to populate Active
direcotry with Exchange 5.5 data using active directory connection (ADC).